1. Field of the Invention
The present invention relates to the field of microcomputers, and more particularly to modulator/demodulator sets for data communication over phone lines between computers.
2. Prior Art
Microcomputer systems of various configurations for personal use and entertainment have been sold in large quantities over the past few years. Some of these computer systems such as the Atari 400 and 800 computers, manufactured by Atari, Inc., have program cartridge receptacles whereby, when a program cartridge is plugged there into, the read-only memory in the program cartridge is connected to the computer system address and data busses, power, ground and synchronized timing and control signals. In the computers just mentioned, there is a shielding cover which closes over the program cartridges, with a lock-out which prevents operation of the computer with the cover open. The computers of course also have other connection capabilities such as, by way of example, cassette recorder input and output connections, game paddle connections, etc.
Computers of the foregoing type are relatively inexpensive and provide substantial computing and game-playing capabilities for their cost. Also their capabilities may be extended by using various peripheral devices therewith such as, by way of example, a modem for data communication over a phone line. Modems could be connected to such machines either by opening the computer case to make direct connections to the PC board, or by providing the modem as a more conventional free-standing device and coupling the modem to the computer through PC board connections provided at the back of the computer. However, opening the computer case to connect modem board to the computer board is quite unattractive, as such computers are generally consumer items and such installation would be beyond the capabilities of most consumers. On the other hand a free-standing modem, while being attractive as being readily user connectable, has certain unattractive aspects such as requiring separate free-standing enclosure, relatively expensive connectors, cabling, etc. In that regard, the cost of accessory or peripheral equipment for computers of this general type is an extremely important consideration, as the computers themselves are relatively reasonably priced and all but the lowest cost accessory or peripheral equipment would be out of proportion to the price of the computers themselves. Accordingly, the purpose of the present invention is to provide a modem and a means for connecting the modem to a computer of the foregoing type at the lowest possible cost which is readily user installable.